CMS uses a [[flat file system]], pointers to all files on the disk are stored in the MFD. The MFD contains an array of disk addresses of blocks containing ''File Status Table'' (FST) (directory) entries. Following these is information describing the status of the disk used by allocation. Each FST block contains twenty 40-byte FST entries, each describing a file. The contents of one FST entry are:<ref name="DataAreas">{{cite book|last1=IBM Corporation|title=IBM Virtual Machine Facility/370: Data Areas and Control Block Logic|date=February 1976|page=179|url=http://bitsavers.informatik.uni-stuttgart.de/pdf/ibm/370/VM_370/plm/SY20-0884-0_VM370_Rel_3_Data_Areas_and_Control_Block_Logic_Feb76.pdf}}</ref>
